On February 24, 2011, the EPA held the first of three scheduled listening sessions in Arlington, Virginia, to obtain public input regarding a potential addition of a vapor intrusion component to the Hazard Ranking System ("HRS"). The HRS is the principal mechanism utilized by the EPA to place sites on the CERCLA National Priorities List ("NPL"), commonly referred to as the Superfund Site List. EPA is considering adding a new screening mechanism to the HRS enabling sites with vapor intrusion contamination to be evaluated for placement on the NPL. "This potential addition would allow the HRS to directly consider the human exposure to contaminants that enter building structures through the subsurface environment." 76 Fed. Reg. 5370 (Jan. 31, 2011).

The question of adding vapor intrusion as a criterion to the HRS was raised last year in a May 2010 Government Accountability Office ("GAO") report (EPA's Estimated Costs to Remediate Existing Sites Exceed Current Funding Levels, and More Sites are Expected to Be Added to the National Priorities List, GAO Report to Congressional Requesters, GAO-10-380, May 2010). The GAO recommended "that the EPA Administrator determine the extent to which EPA will consider vapor intrusion in listing NPL sites and its effect on the number of sites listed in the future." (Emphasis supplied). The full GAO report can be found at https://www.gao.gov/new.items/d10380.pdf.

The second listening session is scheduled for March 16, 2011, in San Francisco, California and the third listening session is scheduled for March 30, 2011, in Albuquerque, New Mexico. For additional information please click here. EPA will be accepting comments on the potential addition of a vapor intrusion component to the HRS until April 16, 2011.